advanced nutrition exam IV Flashcards
food sources of calcium
dairy
seafood WITH bones
main transport of calcium…
calcitrol (vitamin D)
diffusion of Ca
passive, nonsaturatable, nonregulated process
calcium transport
bound to proteins
complexed with sulfate, phosphate, etc
free in blood
protein bound in Ca in equilibrium w ionized Ca2+
how is extracellular ca2+ concentration regulated?
PTH
calcitonin
calcitrol
roles of parathyroid
increases serum Ca2+
decreases bone Ca2+
increases renal Ca2+ absorption
increases Ca2+ intestinal absorption
calcitrol roles
increases serum ca2+
works with PTH in bone Ca2+
increase renal ca absorption
increase intestinal ca absorption
calcitonin
decreases serum ca
increases bone ca
decreases renal ca absorption
nutrients the enhance calcium absorption
vitamin D
sugar + sugar alcohol
protein
nutrients that inhibit calcium absorption
fiber phytic oxalic acid Zn + Mg unabsorbed FAs
osteoblasts
bone-building cells
osteoclasts
resorb bone
RDA Calcium 19-50
1000 mg/day
UL calcium
2500 mg/day
which foods contain up to 350 mg Ca per serving?
dairy, OJ [fortified], tofu, navy beans
nutrients enhancing urinary calcium excretion?
sodium
protein
caffeine
nutrients that may inhibit absorption of calcium
P
Fe
FAs
deficiency of calcium in adults leads to increased risk of….
osteoporosis
food sources of phosphorus
meat, poultry, fish, eggs, milk
cola drinks
absorption of phosphorus
saturable, carrier-mediated, AT
diffusion
which mineral in excess can inhibit phosphorous?
Ca
functions of phosphorus?
bone mineralization nucleic acid formation energy storage and transfer (ATP phosphate bonds) phospholipids acid-base balance
RDA phosphorus
19+ years = 700 mg/day
UL phosphorus 9-70
4g/day
UL phosphorus > 70
3g/day
magnesium dietary sources
nuts, seeds, WG, green leafy vegetables, legumes, lentils, spices, dairy, hard tap h2o
absorption of magnesium
- saturable, carrier-mediated, AT (low mg levels)
2. diffusion passive, concentration dependent (higher mg levels)
magnesium regulation
crosses BB membrane w protein on enterocyte
absorbed BETWEEN cells
pumped across membrane by sodium-dep ATPase
which hormone affects Mg balance?
parathyroid
RDA magnesium 19-30 male
400 mg/day
RDA magnesium 19-30 female
310 mg/day
RDA mag pregnancy
350 mg/day
RDA mg 31+ male
400 mg/day
RDA mg 31+ female
320 mg/day
RDA mg 31+ pregnancy
360 mg/day
factors that contribute to mag deficiency
inadequate intake excess etoh use malabsorptive disorders medications uncontrolled DM + metabolic syndrome
what causes magnesium toxicity?
usually not dietary excess; KIDNEYS excrete Mg rapidly
UL mg
350 mg/day
functions of water in the body
chemical reactions body temp reg lubrication and protection solvent and transport medium maintenance of BV acid base balance
how much BW is intracellular
2/3 (28L)
how much BW is extracellular
1/3 (14L)
how much BW is interstitial?
11 L
how much BW is plasma/intravascular?
3L
AI water for females
2.7 L/day
AI water for males
3.7 L/day
water recommendation based on body weight numbers
25-40 mL/kg BW
which ion strongly affects h2o in ECF?
Na+
what force regulates movement between interstitial space and ECF?
osmotic pressure
what governs the movement across capillary walls and interstitial space?
hydrostatic and colloidal osmotic pressure
osmosis vs osmolarity
osmosis = movement of h2o -> semipermeable membrane in response to different solute concentrations osmolarity = solute particle concentration of a fluid
which ion is the major ion INSIDE the cells?
K+
which ion is the major ion OUTSIDE the cells [in ECF]
Na+
hyponatremia
diluted plasma concentration due to overconsumption of h2o
hypernatremia
diluted plasma concentration due to OVERconsumption of water
plasma solute concentrations list
high Na+
low K+
high Cl-
low HCO3-
interstitial fluid concentrations list
high na+
low k
high cl
low hco3
intracellular fluid concentrations list
low na
high k
high po4-
which two hormones correct imbalances in body’s fluid and sodium levels?
vasopressin
renin-angiotensis-aldosterone system
what does vasopressin respond to?
slight increases in ECF osmolarity
physiological responses to vasopressin
resorbption of h2o in kidneys
stimulates thirst
increases BP by vasoconstriction of arterioles
function of renin
enhances na and cl reabsorption
